1. Field of the Application
The disclosure is related to methods of fabricating an active device array and an organic light emitting diode array.
2. Description of Related Art
With rapid development of image display technologies, cathode ray tube (CRT) displays that used to be applied in televisions or computers have been gradually replaced by flat panel displays (FPDs). Comparing with a rigid carrier substrate such as glass substrate, a flexible substrate such as plastic substrate has the characteristics of good flexibility and desirable impact endurance. Therefore, a flexible display having the active devices, such as the thin film transistors, disposed on the flexible substrate are recently provided.
It is worthy to note that the flexible substrate has greater coefficient of thermal expansion than the glass substrate. During the fabrication of the flexible display, the flexible substrate can expand or shrink due to the temperature change in the environment. Therefore, the problems of poor alignment accuracy and stringent temperature restriction are requested to be overcome when fabricating the thin film transistor on the flexible substrate.
Technologies of forming thin film transistor on the flexible substrate by using a roll-to-roll process have been provided in U.S. Pat. Nos. 7,202,179, 7,248,306, 7,341,839, 7,541,227, 7,521,313, 7,585,424, US Patent Publication No. 2006/0134922, US Patent Publication No. 2007/0040491, US Patent Publication No. 2007/0117278, US Patent Publication No. 2008/0185591, US Patent Publication No. 2008/0248605, U.S. Pat. No. 7,248,306, US Patent Publication No. 2006/0017875, and US Patent Publication No. 2008/0248605. Generally, the roll-to-roll process has the advantages of low cost for fabrication factor and facilitating the fabrication of the device with large area, which is suitable for being applied in the process for fabricating the thin film transistors.